Camry I4 vs '09 Corolla XRS

[radmanGTO]

All ... because of my now extended driving miliage each day (120 miles), I am considering moving down to the more fuel efficient Corollas. Trying to maintain a reasonable sporty mode, I am looking at the Corolla S and XRS. The S is quite the gas mizer with reports of the 1.8L between 35-40 mpg on the highway.

What I really want is the XRS. But, it ONLY EPA's @ 30mpg highway. This same engine in the Camry that is rated @ 31mpg. Numerically, not much difference. But with the Camry carrying almost 1000 pounds more than the much lighter Corolla .... what gives ...???

The S and XRS have very little axle ratio difference as the rpm diff for the 5 spds is only about 30rpm diff at 60 mph. So, the only thing I can think is different ratios betwen the Camry and the XRS. BUT, it would not make much sense for Toyota to make a special ratio case just for the limited quantity XRS.

Any one out there have any real-live experience with the XRS miliage and possibly why it is rated so much lower than I would have expected ???? Your help is always appreciated.

Regards,
Radman

[Somedude]

You should consider 8th gen Honda Civic, even the regular brand has 140 crank hp with the 1.8L and gets about similar gas milage as the Corolla S.

[philosophicaljt]

The XRS is just a scion TC in disguise isn't it? Check the Scion's gearing.

[Sebas007]

I liked to test drove the Matrix XR with the 2.4L manual tranny. First, I wanted to try the Corolla XRS with the 2.4L and manual tranny. They share the same platform, engine and most of whole component. I was really pleased with the driving. I miss driving manually !! However...I don't know if I will ever buy a little car again. Time make priorities order change.

[panic]

If most of your driving is high cruising speed, the weight and maximum power have little effect on mileage

In traffic they have a huge effect - every time you stop, all the power used to accelerate the car up to speed is thrown away by the brake rotors as heat, then you get to do it all over again).

Bigger effect: gearing, drag coefficient.

After 35 Mph most of your power goes for pushing the box through the air.
PS: body kits reduce mileage in most cases, some even reduce cooling.

[gnegroni]

The XRS is just a scion TC in disguise isn't it? Check the Scion's gearing.

Scion tCs:
1st Gear Ratio: 3.538:1
2nd Gear Ratio: 2.045:1
3rd Gear Ratio: 1.333:1
4th Gear Ratio: 0.972:1
5th Gear Ratio: 0.775:1
Final Drive 4.24?

My manual 5-speed Solara 2.4L:
3.538
2.045
1.333
0.972
0.731
FD 3.944

2009 Corolla XRS gear ratios:
First Gear Ratio : 3.54:1
Second Gear Ratio : 2.05:1
Third Gear Ratio : 1.33:1
Fourth Gear Rato : 0.97:1
Fifth Gear Ratio : 0.73:1
Reverse Ratio : 3.58:1
Final Drive Axle Ratio : 4.24:1

It seems that the Corolla has the 5th gear ratio of the Solara (better for economy than the Scion tC) but has the final drive ratio of the Scion tC (not better for economy, but faster acceleration than Solara 2.4L). This helps with the 30mpg rating vs the 27mpg of the scion tC. Do remember that the Solara 2.4l Manual was downrated to 31mpg. Either way, the 2008 EPA estimates are for very aggressive driving. I almost always do better than the EPA estimates.

[PXLpainter]

Uhhh... what does ANY of this have to do with Gen 2 Solaras???

[radmanGTO]

This is called a transfer of knowledge.

Sorry that it bothers you. Suggest you ignore those members who gave their input and consider reading other posts.

Thanks to you that replied.

As closure, it obvious that the final drive ratio with a lack of a 6sp hurts this XRS in the current need for higher efficiency.

Regards all,
Radman

[gnegroni]

This is called a transfer of knowledge.

Sorry that it bothers you. Suggest you ignore those members who gave their input and consider reading other posts.

Thanks to you that replied.

As closure, it obvious that the final drive ratio with a lack of a 6sp hurts this XRS in the current need for higher efficiency.

Regards all,
Radman

I think what PXL meant was that it should have been posted under the General section. Either way, maybe you should just put bigger tires on the XRS, altering the speedo so that you make the gear ratios match?

[panic]

Not to dwell on trivia, but it's a misnomer to refer to the axle ratio (above) as the "final drive ratio".
The final drive ratio is the gear ratio in high gear (5th, 6th, whatever in the transmission) ratio × the axle (ring & pinion in the differential) ratio:

Scion: .775 5th gear ratio × 4.24 axle ratio = 3.286:1

Solara: .731 5th gear ratio × 3.944 axle ratio = 2.883:1

Corolla: .73:1 5th gear ratio × 4.24 axle ratio = 3.0952:1

The engine speed, torque multiplication, and Mph/1000 RPM will be in direct proportion to this figure (assuming equal tire OD).

[gnegroni]

Not to dwell on trivia, but it's a misnomer to refer to the axle ratio (above) as the "final drive ratio".
The final drive ratio is the gear ratio in high gear (5th, 6th, whatever in the transmission) ratio × the axle (ring & pinion in the differential) ratio:

Scion: .775 5th gear ratio × 4.24 axle ratio = 3.286:1

Solara: .731 5th gear ratio × 3.944 axle ratio = 2.883:1

Corolla: .73:1 5th gear ratio × 4.24 axle ratio = 3.0952:1

The engine speed, torque multiplication, and Mph/1000 RPM will be in direct proportion to this figure (assuming equal tire OD).

Thanks for the correction. BTW, can you assume that 3.0952/2.883 (~7%) could be translated into ~7% bigger tires to effectively lower revs and boost economy a bit?

[panic]

Yes as to the math, in that the tire OD has that effect.
However: how much of it is lost if the new tire is wider, heavier, stickier (rolling resistance)?

If the car height goes up (new OD - old OD ÷ 2), does more air go under the car, increasing aero drag?

I would guess that Toyota has been careful to make sure that any change in local air pressure (down-force, front vs. rear) remains constant or produces light understeer (not oversteer) at high speed, and raising the car will change that - but I don't know how much, or which way.

Probably a net gain in mileage, but I'd certainly try to borrow the tires before $pending.

[gnegroni]

Yes as to the math, in that the tire OD has that effect.
However: how much of it is lost if the new tire is wider, heavier, stickier (rolling resistance)?

If the car height goes up (new OD - old OD ÷ 2), does more air go under the car, increasing aero drag?

I would guess that Toyota has been careful to make sure that any change in local air pressure (down-force, front vs. rear) remains constant or produces light understeer (not oversteer) at high speed, and raising the car will change that - but I don't know how much, or which way.

Probably a net gain in mileage, but I'd certainly try to borrow the tires before $pending.

I don't think there will be more rolling resistance as long as the tire isn't wider. Definitely need to borrow tires before dishing out the $$$.

[panic]

Actually, despite the popular perception, V and Z rated tires are less sticky at cruising speed than H rated.