Question about manual vs. automatic

[jhu]

Originally posted by: PhoKingGuy

Originally posted by: mariok2006

Originally posted by: DeathBUA

Originally posted by: mariok2006
I just drove my friends 06 civic today and it did 2100rpm at 70mph! That freaked me out for a second since I'm used to 4cyl cars hovering around 3k+ at that speed. I wonder what the bfsc is at that rpm compared to 3000. I would imagine the bsfc would be better at 3000 and therefore it would get better mileage...

Plus my car will automatically shut the engine off once your foot is lifted off the accelerator even at 70mph thus momentarily consuming zero fuel but without having to do something crazy like turn the car off.

Most if not all modern cars do this.

No

Euro spec VW diesels do, but other than hybrids I dont think any other car does that. The engine physically turns off, not keeps spinning

He probably meant the fuel injectors shut off, which happens in most cars these days. There are non-hybrids where the engine does shutoff, like the Chevy Silverado Hybrid (which isn't really a hybrid).

 

[fleabag]

Originally posted by: mariok2006

Originally posted by: fleabag

Originally posted by: mariok2006
I just drove my friends 06 civic today and it did 2100rpm at 70mph! That freaked me out for a second since I'm used to 4cyl cars hovering around 3k+ at that speed. I wonder what the bfsc is at that rpm compared to 3000. I would imagine the bsfc would be better at 3000 and therefore it would get better mileage...

Just because the ENGINE is more efficient at a given RPM, it doesn't mean that it won't use more fuel. I'd find it hard to believe that the car could use less fuel at 3000rpm than at 2100rpm. BSFC really only helps when trying to find the point at which the engine produces the most power for a given amount of fuel. Here is an example:

a 50CC two stroke engine could use a pint of fuel in 5 hours of idling while a 1500cc engine could use a pint of fuel in 30 minutes of idling. This however doesn't mean that the 50cc engine is more efficient than the 1500cc, it just means that the 50cc engines consumes less fuel. So while a moped may get 60-80mpg and a prius gets 45mpg, the prius is extremely efficient compared to the moped considering that the moped only carries around 400lbs (the bike an passenger) while the prius carries like 3500-4000lbs+ [the car and passenger(s)].

BSFC is mostly of interest to hypermilers who perform DFCO (Deceleration Fuel Cutoff) because they attempt to accelerate the vehicle using the highest BSFC and then turn off the engine to coast. You won't achieve the best BSFC while cruising unless you so happen to be cruising up a high enough gradient that allows you to load the engine to that point. Again, that would only make that particular situation "as efficient as it gets" but does not mean it will use less fuel than cruising a similar length of road but with no or negative gradient.

Efficiency matters, fuel consumption matters, the key is to do well in both.

What you didn't consider is throttle opening. Even though the rpm is lower, if the throttle opening is greater, teh car will use more fuel. If at 3000rpm the throttle opening is less than it is at 2100rpm to maintain 70mph, the car will get better mileage at 3000rpm.

I realize that ICEs are most efficient at WOT, but like you said workin/workout doesn't mean its getting the best mileage.

But if the throttle opening is smaller at a higher RPM because of the reduced load, then you've got the issue of pumping losses which is why Close to WOT (without the mixture being fully enriched) is more efficient inherently. Also at a higher RPM you've got to contend with faster spinning reciprocating mass and it's usually better to run at a lower RPM but not so low that due to things like valve lift and timing, you're not efficiently using the fuel. If you can get perfect valve lift and timing while at cruising speeds on the highway (1800rpm=60 for example), the engine will be much closer to its BSFC.

So, to make a car the very most efficient at cruising speed of like 60mph, technically what you could do is first find exactly out how much power you need, find the lowest RPM then engine can function, have all the timing like the ignition, valve, fuel, etc. all perfectly 'maxed out' at that specific RPM, and then have the transmission geared accordingly to match that very most efficient RPM.

While this car wouldn't be very practical, what it would allow you to do is cruise at the highest BSFC AND be using the least amount of fuel possible. But even then, what you'd have to do is downsize the engine and then do the very thing I mentioned above once again due reduction in mass you're moving around.

 

[exdeath]

Originally posted by: PhoKingGuy

Originally posted by: mariok2006

Originally posted by: DeathBUA

Originally posted by: mariok2006
I just drove my friends 06 civic today and it did 2100rpm at 70mph! That freaked me out for a second since I'm used to 4cyl cars hovering around 3k+ at that speed. I wonder what the bfsc is at that rpm compared to 3000. I would imagine the bsfc would be better at 3000 and therefore it would get better mileage...

Plus my car will automatically shut the engine off once your foot is lifted off the accelerator even at 70mph thus momentarily consuming zero fuel but without having to do something crazy like turn the car off.

Most if not all modern cars do this.

No

Euro spec VW diesels do, but other than hybrids I dont think any other car does that. The engine physically turns off, not keeps spinning

Here we go again....

DFCO - Deceleration Fuel Cut Off:

When the throttle is closed (no power demanded) and the engine is kept above idle via external mechanical means (eg: car's forward momentum), the engine is effectively shut off (fuel and ignition are interrupted). Engine power is restored to prevent stalling once it gets close to idle.

 

[exdeath]

Originally posted by: cr2250

Exactly, this is what I was observing, I was comparing 4cyl engines in general. Thanks for the info, it's helped me understand the topic much better. My next car is going to be an auto, tired of shifting in california traffic : /

My numbers were wrong (reverse gear ratios were right next to final drive 😱). If I wasn't in a hurry this morning, I would have raised an eyebrow to that 2.xx final ratio on a 4 cyl.

But the concept is what is important; ATs get away with using taller gearing due to torque multiplication, which effectively creates two virtual gear sets for both accelerating and cruising out of the single physical gear set.

Of course there are always exceptions however, notably with engines with so little torque that not even the torque converter can help with taller gears. On such engines, powering the AT is so demanding that you might see shorter gears in the AT, in which case the manual will perform better in both acceleration and cruise conditions. Anything in the 2.0L range though should have enough power to run a AT with taller gears and leverage the torque converter.

 

[jhu]

Originally posted by: exdeath

Originally posted by: cr2250

Exactly, this is what I was observing, I was comparing 4cyl engines in general. Thanks for the info, it's helped me understand the topic much better. My next car is going to be an auto, tired of shifting in california traffic : /

My numbers were wrong (reverse gear ratios were right next to final drive 😱). If I wasn't in a hurry this morning, I would have raised an eyebrow to that 2.xx final ratio on a 4 cyl.

But the concept is what is important; ATs get away with using taller gearing due to torque multiplication, which effectively creates two virtual gear sets for both accelerating and cruising out of the single physical gear set.

Of course there are always exceptions however, notably with engines with so little torque that not even the torque converter can help with taller gears. On such engines, powering the AT is so demanding that you might see shorter gears in the AT, in which case the manual will perform better in both acceleration and cruise conditions. Anything in the 2.0L range though should have enough power to run a AT with taller gears and leverage the torque converter.

You gave the example calculations using the gen 3 Camry. However, official EPA numbers are the same for the automatic and the manual.. What gives? Also, has anyone ever seen a manual Camry? They're like unicorns over on the west coast.

 

[exdeath]

Originally posted by: jhu

Originally posted by: exdeath

Originally posted by: cr2250

Exactly, this is what I was observing, I was comparing 4cyl engines in general. Thanks for the info, it's helped me understand the topic much better. My next car is going to be an auto, tired of shifting in california traffic : /

My numbers were wrong (reverse gear ratios were right next to final drive 😱). If I wasn't in a hurry this morning, I would have raised an eyebrow to that 2.xx final ratio on a 4 cyl.

But the concept is what is important; ATs get away with using taller gearing due to torque multiplication, which effectively creates two virtual gear sets for both accelerating and cruising out of the single physical gear set.

Of course there are always exceptions however, notably with engines with so little torque that not even the torque converter can help with taller gears. On such engines, powering the AT is so demanding that you might see shorter gears in the AT, in which case the manual will perform better in both acceleration and cruise conditions. Anything in the 2.0L range though should have enough power to run a AT with taller gears and leverage the torque converter.

You gave the example calculations using the gen 3 Camry. However, official EPA numbers are the same for the automatic and the manual.. What gives? Also, has anyone ever seen a manual Camry? They're like unicorns over on the west coast.

1) That's the 2009 Camry with a 5 speed auto, and I have no idea what the gearing is between them. Probably a lot closer than a 4 speed auto? This was to look at top gear cruising RPM at a given speed, not mileage. Though highway mileage is closely related to gearing, other factors such as AT vs MT ECU come into play as well. MT will generally have a richer tune since it can be bogged and loaded harder and MPG will go down; auto will cancel out some of it's inefficiency issues with more gears and MPG will go up, etc. It's never a clear picture.

2) It's a EPA estimate... are they ever right and does anyone actually drive like that?

3) 1995 5 speed here. Solara E153 5 spd sitting under a tarp in the garage awaiting a 3SGTE when I can afford to waste money on a 15 yr old Camry.

 

[Zenmervolt]

Originally posted by: mariok2006
What you didn't consider is throttle opening. Even though the rpm is lower, if the throttle opening is greater, teh car will use more fuel. If at 3000rpm the throttle opening is less than it is at 2100rpm to maintain 70mph, the car will get better mileage at 3000rpm.

Actually, you have it bass-ackwards.

RPM is the single largest driver in the fuel consumption equation. In the situation you describe, the car with the engine running at 2,100 RPM with a larger throttle opening will get better mileage than the car running at 3,000 RPM with a smaller throttle opening assuming that all else is equal.

ZV

 

[overst33r]

Originally posted by: Zenmervolt

Originally posted by: mariok2006
What you didn't consider is throttle opening. Even though the rpm is lower, if the throttle opening is greater, teh car will use more fuel. If at 3000rpm the throttle opening is less than it is at 2100rpm to maintain 70mph, the car will get better mileage at 3000rpm.

Actually, you have it bass-ackwards.

RPM is the single largest driver in the fuel consumption equation. In the situation you describe, the car with the engine running at 2,100 RPM with a larger throttle opening will get better mileage than the car running at 3,000 RPM with a smaller throttle opening assuming that all else is equal.

ZV

As a decent example, let's take my car into account, even though fuel efficiency wasn't a large factor when the car was designed.

If your statement is correct, then I'd be getting better hwy mileage if I was cruising at 2500rpm at 70mph instead of 3700rpm than it does currently, which I don't believe to be the case.

I usually get worse mileage when I cruise below 3000rpm because I need to have a larger throttle opening to maintain speed. My torque curve directly reflects this. There's literally nothing below 3000rpm, even though it's linear.

Assuming you are correct, which you usually are...

Out of ignorance, why don't more cars (economy cars or cars meant for fuel efficiency) cruise at the lowest possible rpm without lugging the engine? Yes it would sacrifice passing power, but that's not the point.

 

[Zenmervolt]

Originally posted by: mariok2006

Originally posted by: Zenmervolt

Originally posted by: mariok2006
What you didn't consider is throttle opening. Even though the rpm is lower, if the throttle opening is greater, teh car will use more fuel. If at 3000rpm the throttle opening is less than it is at 2100rpm to maintain 70mph, the car will get better mileage at 3000rpm.

Actually, you have it bass-ackwards.

RPM is the single largest driver in the fuel consumption equation. In the situation you describe, the car with the engine running at 2,100 RPM with a larger throttle opening will get better mileage than the car running at 3,000 RPM with a smaller throttle opening assuming that all else is equal.

ZV

As a decent example, let's take my car into account, even though fuel efficiency wasn't a large factor when the car was designed.

If your statement is correct, then I'd be getting better hwy mileage if I was cruising at 2500rpm at 70mph instead of 3700rpm than it does currently, which I don't believe to be the case.

I usually get worse mileage when I cruise below 3000rpm because I need to have a larger throttle opening to maintain speed. My torque curve directly reflects this. There's literally nothing below 3000rpm, even though it's linear.

Assuming you are correct, which you usually are...

Out of ignorance, why don't more cars (economy cars or cars meant for fuel efficiency) cruise at the lowest possible rpm without lugging the engine? Yes it would sacrifice passing power, but that's not the point.

In this one instance, fleabag has actually given the main reasons why low RPM + large throttle opening is more efficient, albeit in a more convoluted way than is necessary.

To move a given car at a given speed, a specific amount of power is require. Typically this is on the order of 20-30 hp to move a car at ~65 mph on a flat asphalt road without a significant head or tail wind.

As you have acknowledged, engines are most efficient at turning fuel into power when they operate near WOT (in modern EFI design there is usually mixture enrichment at WOT that increases fuel consumption, but we'll ignore that for a theoretical discussion). Since the HP requirement at a given speed is known and fixed, the most efficient way to cruise is to operate the engine under the conditions for which it most efficiently turns fuel into that specific amount of power. Generally this is at or near WOT at low RPM.

When the throttle is only partially open, a certain amount of addition hp is required to pull air past the restrictive throttle. This extra horsepower is effectively "thrown away".

So, if we know that the car itself needs, say 25 hp to cruise at 65 mph and that at WOT only 1 hp is consumed by the engine to overcome friction but that at 25% throttle 4 hp additional hp is consumed to overcome pumping losses, you can see that a higher RPM with a smaller throttle opening is going to require more power in total than a lower RPM with WOT. (These numbers are all made up for illustrative purposes.) More power required and less efficient at producing that power all conspire to make the high-rpm small throttle opening option consume more fuel.

The best example of this in real-world practice is the Chevrolet Corvette, which uses an incredibly tall 6th gear to drop the engine to very low RPM on the freeway and thereby achieve rather stunning highway mileage given the engine's size and power output.

You actually answer your own question when you point out that gearing economy cars to cruise at the lowest possible RPM without lugging the engine would sacrifice passing power, though you're right that it's not that simple.

Firstly, varying loads on the car affect when an engine will lug; with the car empty of everything but the driver the gearing could be taller than if the car were loaded to the full GVWR. Not only that, but it's essentially certain that people will load cars beyond the GVWR rating with reasonable frequency. Because of this, there needs to be enough leeway to prevent the engine from lugging in top gear even if the car is stuffed to the gills with NFL Defensive Linemen.

Also, there are hills and strong headwinds encountered in real-world driving and no-one wants to drive a car that requires a downshift every time the road starts to incline even slightly, so more leeway must be built in.

Additionally, there are demographic concerns. The majority of small cars are bought by people who don't do large amounts of long-distance freeway travel; most of these cars spend the majority of their time at 55mph or below and as a result tend to be geared such that they can be in their top gear by about 45 or 50 mph. This means that at freeway speeds of 65-75 mph the cars are already well above the minimum speed for their top gear. This sacrifice is acceptable because the gains in fuel mileage at lower speeds are far greater than the sacrifice in highway mileage. The cost of adding an additional gear to the manual transmission is generally judged not to be worth it.

Finally, there's just general feel. When the gap between two gears is too great it creates a negative impression on the driver, especially if the engine doesn't make much torque. If 5th gear in economy cars were designed to have a minimum speed of 65 mph, there would be two options: 1) space out the lower gears more widely which would make the car feel sluggish in most situations, or 2) leave gears 1-4 as normal and have a huge gap between 4th, which could be used by 35-40 mph, and 5th, which would mean either lugging the engine at 55-60 mph or revving abnormally high in that speed range. That's a gap that would be noticeable and annoying to drivers.

I'm sure there are other reasons as well, but those seem to be the main ones that come readily to mind.

 

[overst33r]

Originally posted by: Zenmervolt

Originally posted by: mariok2006

Originally posted by: Zenmervolt

Originally posted by: mariok2006
What you didn't consider is throttle opening. Even though the rpm is lower, if the throttle opening is greater, teh car will use more fuel. If at 3000rpm the throttle opening is less than it is at 2100rpm to maintain 70mph, the car will get better mileage at 3000rpm.

Actually, you have it bass-ackwards.

RPM is the single largest driver in the fuel consumption equation. In the situation you describe, the car with the engine running at 2,100 RPM with a larger throttle opening will get better mileage than the car running at 3,000 RPM with a smaller throttle opening assuming that all else is equal.

ZV

As a decent example, let's take my car into account, even though fuel efficiency wasn't a large factor when the car was designed.

If your statement is correct, then I'd be getting better hwy mileage if I was cruising at 2500rpm at 70mph instead of 3700rpm than it does currently, which I don't believe to be the case.

I usually get worse mileage when I cruise below 3000rpm because I need to have a larger throttle opening to maintain speed. My torque curve directly reflects this. There's literally nothing below 3000rpm, even though it's linear.

Assuming you are correct, which you usually are...

Out of ignorance, why don't more cars (economy cars or cars meant for fuel efficiency) cruise at the lowest possible rpm without lugging the engine? Yes it would sacrifice passing power, but that's not the point.

In this one instance, fleabag has actually given the main reasons why low RPM + large throttle opening is more efficient, albeit in a more convoluted way than is necessary.

To move a given car at a given speed, a specific amount of power is require. Typically this is on the order of 20-30 hp to move a car at ~65 mph on a flat asphalt road without a significant head or tail wind.

As you have acknowledged, engines are most efficient at turning fuel into power when they operate near WOT (in modern EFI design there is usually mixture enrichment at WOT that increases fuel consumption, but we'll ignore that for a theoretical discussion). Since the HP requirement at a given speed is known and fixed, the most efficient way to cruise is to operate the engine under the conditions for which it most efficiently turns fuel into that specific amount of power. Generally this is at or near WOT at low RPM.

When the throttle is only partially open, a certain amount of addition hp is required to pull air past the restrictive throttle. This extra horsepower is effectively "thrown away".

So, if we know that the car itself needs, say 25 hp to cruise at 65 mph and that at WOT only 1 hp is consumed by the engine to overcome friction but that at 25% throttle 4 hp additional hp is consumed to overcome pumping losses, you can see that a higher RPM with a smaller throttle opening is going to require more power in total than a lower RPM with WOT. (These numbers are all made up for illustrative purposes.) More power required and less efficient at producing that power all conspire to make the high-rpm small throttle opening option consume more fuel.

The best example of this in real-world practice is the Chevrolet Corvette, which uses an incredibly tall 6th gear to drop the engine to very low RPM on the freeway and thereby achieve rather stunning highway mileage given the engine's size and power output.

You actually answer your own question when you point out that gearing economy cars to cruise at the lowest possible RPM without lugging the engine would sacrifice passing power, though you're right that it's not that simple.

Firstly, varying loads on the car affect when an engine will lug; with the car empty of everything but the driver the gearing could be taller than if the car were loaded to the full GVWR. Not only that, but it's essentially certain that people will load cars beyond the GVWR rating with reasonable frequency. Because of this, there needs to be enough leeway to prevent the engine from lugging in top gear even if the car is stuffed to the gills with NFL Defensive Linemen.

Also, there are hills and strong headwinds encountered in real-world driving and no-one wants to drive a car that requires a downshift every time the road starts to incline even slightly, so more leeway must be built in.

Additionally, there are demographic concerns. The majority of small cars are bought by people who don't do large amounts of long-distance freeway travel; most of these cars spend the majority of their time at 55mph or below and as a result tend to be geared such that they can be in their top gear by about 45 or 50 mph. This means that at freeway speeds of 65-75 mph the cars are already well above the minimum speed for their top gear. This sacrifice is acceptable because the gains in fuel mileage at lower speeds are far greater than the sacrifice in highway mileage. The cost of adding an additional gear to the manual transmission is generally judged not to be worth it.

Finally, there's just general feel. When the gap between two gears is too great it creates a negative impression on the driver, especially if the engine doesn't make much torque. If 5th gear in economy cars were designed to have a minimum speed of 65 mph, there would be two options: 1) space out the lower gears more widely which would make the car feel sluggish in most situations, or 2) leave gears 1-4 as normal and have a huge gap between 4th, which could be used by 35-40 mph, and 5th, which would mean either lugging the engine at 55-60 mph or revving abnormally high in that speed range. That's a gap that would be noticeable and annoying to drivers.

I'm sure there are other reasons as well, but those seem to be the main ones that come readily to mind.

Those are some excellent points that make complete sense, but didn't even come to thought for me.

I'm still a bit unclear on the acceleration bit. If accelerating in the min bsfc range is best, why is cruising in min bsfc not?

I guess I'll go experiment a bit more with my car.

 

[jhu]

Those are some excellent points that make complete sense, but didn't even come to thought for me.

I'm still a bit unclear on the acceleration bit. If accelerating in the min bsfc range is best, why is cruising in min bsfc not?

I guess I'll go experiment a bit more with my car.

When accelerating, you're actually using that power to its maximum extent. Now if you were to be able to cruise at min bsfc @ 65 mph, the that would be ideal (but the engine would basically have no passing power). In most cars, cruising at min bsfc means you'd be traveling at well over 100 mph.

 

[Hellotalkie]

Yeah I was reading online about my Hyundai Tibby 05, I guess it is known that the RPM's dont drop significantly when I switch gears. Say im going 50 mph in 4th gear, its at 3k rpm, I put it in 5th gear, drops maybe 500. I speed up to 65 and its already at 3100k. I go to 75 and its hitting 3500, and then 80 is 4k. Sad that for me to go 80 my rpms are pretty high

 

[overst33r]

When accelerating, you're actually using that power to its maximum extent. Now if you were to be able to cruise at min bsfc @ 65 mph, the that would be ideal (but the engine would basically have no passing power). In most cars, cruising at min bsfc means you'd be traveling at well over 100 mph.

Why wouldn't it have passing power? min bsfc usually occurs at about 35% of redline RPM, in which most cars have plenty of passing power...

 

[Demon-Xanth]

My 5 speed manual only spins about 2200RPM on the freeway, my cousin's 6 speed spins about 1700.

...it depends on the car, not the presence of a clutch 🙂

 

[Zenmervolt]

Why wouldn't it have passing power? min bsfc usually occurs at about 35% of redline RPM, in which most cars have plenty of passing power...

Min BSFC also occurs at or very near WOT. If the car is geared such that you need to be at or near WOT just to maintain speed, you aren't going to have any passing power regardless of RPM.

 

[sdifox]

what year is it?

 

[vshah]

heh..that's nothing. my stupid SI buzzes along at 4000RPM at 75mph. in SIXTH gear.

i still love it though.

 

[PlasmaBomb]

Brake specific fuel consumption taken from Autospeed.com. Colour coded, lower values indicate less fuel consumed per BHP.

 

[fleabag]

Brake specific fuel consumption taken from Autospeed.com. Colour coded, lower values indicate less fuel consumed per BHP.

As nice as that map is, to really get a good idea of BSFC you'll need a 3D map..

 

[alkemyst]

No, automatics are NOT considered standard. They are made largely for fat lazy Americans. Many cars in Europe are manual transmission, I was in Spain in 2008 and saw almost zero automatic transmission cars...and almost zero SUVs and trucks for that matter.

fail...manuals are more common overseas because most are driving with engines smaller than an average motorcycle here and an automatic would bog them down.

SUVs and Trucks due to roadtax not anything else.

I am sure if you ever made it to the autobahn you'd be impressed hitting 100.

 

[Hellotalkie]

so question...
say I drive average 75mph to 80mph on highway.
My rpms are around 3600 - 4000k CONSTANT
is this really bad for the engine?
I always thought anything about 3500 constant is really straining the engine
but in order for me to drive my high way speeds, thats the only way.
Its the 2.0 4cyl tibby 05 (5speed)

 

[overst33r]

so question...
say I drive average 75mph to 80mph on highway.
My rpms are around 3600 - 4000k CONSTANT
is this really bad for the engine?
I always thought anything about 3500 constant is really straining the engine
but in order for me to drive my high way speeds, thats the only way.
Its the 2.0 4cyl tibby 05 (5speed)

Not at all. The engine is designed to operate constantly in the range below the redline. You can sit at 4000 for hours on end. It will NOT be harmful to your engine. If it was harmful, the engineers would have redlined your car at 3500rpm 😉

 

[fleabag]

Not at all. The engine is designed to operate constantly in the range below the redline. You can sit at 4000 for hours on end. It will NOT be harmful to your engine. If it was harmful, the engineers would have redlined your car at 3500rpm 😉

That's wrong, and I have a vague idea of why it's wrong but can't elaborate. Someone else needs to pitch in and explain to this guy why running a car's engine half way up to its redline is a great way to cause it to wear down prematurely. It's usually only racing enhanced vehicles that are actually capable of such operation while most of the time, cars are intended to run at a lower rpm for a longer period of time and higher RPM for a shorter period of time. Again, I can't name specifics as to why it is this way but I'm fairly certain of it.

 

[PhoKingGuy]

That's wrong, and I have a vague idea of why it's wrong but can't elaborate. Someone else needs to pitch in and explain to this guy why running a car's engine half way up to its redline is a great way to cause it to wear down prematurely. It's usually only racing enhanced vehicles that are actually capable of such operation while most of the time, cars are intended to run at a lower rpm for a longer period of time and higher RPM for a shorter period of time. Again, I can't name specifics as to why it is this way but I'm fairly certain of it.

🙁

So by your logic everyone with an S2000 needs a rebuild by 50k?

 

[fleabag]

🙁

So by your logic everyone with an S2000 needs a rebuild by 50k?

Yes? Also the engine in the S2000 is a tad more advanced (understatement) than say an engine in a Corolla or Civic...