have caddy, need tips :)
 

Hi guys, I need some tips for eeking more MPG out of my car. I have an 05 caddy cts 3.6L with the 6 speed manual transmission. I have a suburban route to work and back, about 5 miles each way, I drive to work, home for lunch, then back for the PM session 5 days per week and one trip for the Saturday morning session. There's a brief section of 55mph but most is 45 with 6 stoplights that you never make ;)

I've had the car for about a year, I've wanted a manual transmission car for 25 years and finally got one :) I love the comfy seats, quiet smooth ride, nice stereo, dual climate control. You know, all of the comfy things most caddy's have. It's pretty fast too, the thing digs hard with the RPM's get around 3K. But I'm not a fast driver, I wouldn't mind going to the track someday to learn how to drive fast but I like to be a smooth driver.

Anyway, I'm getting 21-23mpg on this loop. I'm happy with it but if there is a way to get more I'd like to try it. It seems best when I shift early and keep the rpm's low, I drop it into 6th at 40mph every chance I get. I like to roll along in neutral. I try to go easy towards reds or what I think are "soon to be reds". I can make some corners in 4th gear (hold on!) I accelerate pretty slowly, I try to keep in a tall enough gear so I'm not quite lugging. I bundle up in the winter and usually only turn on the ventilation when the windows fog (it's in a garage so it's above freezing even in winter when I start out). I do like my AC in the summer (used it today in fact..) ....hey it's a luxury car, OK? :)

So any general tips you've got I'd appreciate. I've got some specific questions....

-accelerating...I've read sometimes brisk acceleration is better, is this something you have to try and see or is it true (or false?). I've read things like "75% throttle" but I'd be doing 0-60 in 8 seconds with that, especially if I let the rpm's get a little higher.

-tires..I've got bridgestone Turanza's at 30 psi because that's what it says on the door but the tire says max pressure 51 psi. Can I take'em up to 51psi? I don't want to make the car uncontrollable....but what is the deal with PSI anyway?

It's a 255hp 3510 pound car with a coefficient of drag of 0.31. EPA ratings are 15/24 with combined rating of 18

Thanks for the comments guys :)

Joe

I hear these things do WONDERS for gas mileage.

Best mod for MPGs

Typically, peak engine efficiency happens at low RPMs and heavy throttle. Opening the throttle plate, by itself, improves efficiency, but if you press the gas pedal too hard, the ECU enriches the fuel mixture and quickly eliminates your savings. My Subaru (2.2L 5MT) experienced quite leisurely acceleration and relatively good gas mileage when I used 85% throttle and upshifted at 2000 RPM.

Tires: it's safe to go up to the sidewall max pressure. The ride is harsher and noisier, but I think you'll like 51psi anyway.

+1

Ride around with that mod for a few weeks, and you'll gain an appreciation for DWL, frontal area reduction, route selection, methods for shortening and combining trips... it's great. Some people have also managed a permanent weight reduction as a result of Madison's suggestion.

So you're saying keep the rpm's low but give the gas pedal a decent push when accelerating?

I commuted by bike 47 times in 2008 for about 620 miles, only managed 5X in 2009 (switched jobs) but your right, the bicycle is the greatest thing ever for getting to work. Except for all of the damn cars. I liked it better when gas was 4$ per gallon!

Soon I'll be able to post pictures but I'm 100% with you. Just finished the Ironman in New Zealand and I'm keenly aware of my frontal area :)


I hope going to New Zealand for a triathlon doesn't get me kicked off of the ecomodder site.... :)

How many days out of the year do you work?

I've never ridden when gas was high, I just recently (6 months ago) got my bike.

It was 9 days every 2 weeks then, it's 6 days a week now. I should try to ride the bike in a few times per week now. But I really like driving my car! I got in a bit over 3400 miles training last year, seems like some should be getting to and from work :)

I find thot they get yau there foster if yau dant wander.:D

I have found that slow acceleratrion does not seem to help that much with milage. Really fast acceleration hurts milage (because you turn the engine up to high rpm) so finding the happy medium betwixt keeping it in low milage while accelerating for longer and getting into the no acceleration high milage mode sooner. To help with knowing that data is key. Get yourself an mpguino or scan guage if your car does not have instantanious and trip mpg readouts.

Facepalm.jpg

Wander/Wonder is a running Facebook joke I have with my friends, I forgot that you guys aren't them.

Medium, I'll give them a try, I've got the instant and average mpg on the display in the car so I can check it out. I'll report back :)

Installing a block heater for the winters would help. Also, a grill block would improve the aerodynamics and engine warm up time a bit.

The mistake I was making was thinking a "glacer start" (VERY slow excellerating) was using less fuel. As I was corrected here on the forum getting the car into the higher gears is the first key, well if you are taking forever to get up to speed you are driving it longer in the lower gears getting worse mileage!

STUDY the following link. 100+ Hypermiling / ecodriving tips & tactics for better mpg - EcoModder.com Don't read thru it saying to yourself "I knew this" STUDY it. There were a ton of things I thought I knew but REALLY didn't.

One of these being how important it is to NOT stop at stop lights. How do you not stop at a stop light, easy, you short brake and leave the rolling up to the last car while the light turns green. The motor doesn't have to move the mass from a stop, the basic science principle, "It takes less energy to keep a mass moving than to start it from a dead stop".

STUDY the list, I have improved my mileage by over 25% using that list, and I was "practicing" what I THOUGHT were fuel saving driving habits already!

Brian

I'm working thru the list now, there are a ton of good tips there. I have been trying to not come to a stop at traffic lights, it's a whole lot easier when there isn't much traffic. And it is absolutely amazing how far the car will roll in neutral. Dang trouble is that everybody wants to drag race off right up to a red light and I don't want to piss people off too much ;) But trying to not brake unless your going < 20 or 30 has helped a lot.

I'll run some trials about the acceleration and report my findings too :)

Skip gears, 1st till you should shift to third, then third till you should shift to sixth.

0-30 (shift) 30-50 (shift) in 6th at a low RPM.

With that short of a commute, you need a block heater.

I find that how many cars at the light make almost no difference at all. It is all about short braking to slow the car then letting it roll up to the last car until that car starts rolling as well due to the light being green. The hard part that you have to learn is timing the whole thing, cars, and light together. What the cars add is simply an unknowing, when exactly will they move?

But that is all in the learning, I am getting damn good at it.

Brian

The trick is keeping the RPM's down. You want to row through the gears as fast as you can while keeping the RPM's down, and I'd say below 2K on that engine. You might find a different RPM produces better results though, so try experimenting a little.

Go up slowly. 30 is almost certainly too low, and the door placard is based on comfort, not efficiency or grip. You'll probably find the car hits peak grip at a higher pressure. Go up about 5 PSI at a time, and back off a bit when you notice lower grip.

Edit: I see I'm late to the party. :D

No worries I(we) knew whatcha ment, I usualy don't get too excited about typos or misspellings but I figured a good natured ribbing on a good natured sarcastic post was in order:)

fatskiguy:
You already use the manual for its advantages, they are great to run...

did you learn the max torque rpm and horses written?

the v6 is elusive...
meaning the content spot in the throttle may be beyond the actual power curve written.

that is all I can think of..when mentioning v6. It is quite happy as an f1 14,000 rpm dragster...gotta keep after yourself.:rolleyes:

I would go up to 50 psi if the tires are rated for that then come back down to what ever you are comfortable at. newish car with newish shocks in good condition would give me no pause to using max psi, understand though that I would be feeling for bouncy tires as speed increased. In the winter I get some wicked wheel hop when I spin the tires on icy snow.

yeah you can max em up to 51 no problem should make a bit of a difference

So can you really pump up your tires higher than it says on the door? I emailed bridgestone and they said to always use the pressure on the door. I experiment with my bike tire pressures a lot and I'm not opposed to a slightly bouncier ride or a little less grip if the rolling resistance is less. I just don't want them to blow up or anything dramatic like that!

I'd run 50PSI, you will get better MPG because of it.

The pressure on the door is the auto manufactures recomended pressure (for ride and handling). The pressure on the tire is the tire manufactures safe upper limit.

Keep an eye on your tread wear pattern. If you see it wearing more in the center, you have the pressure too high for your vehicle's weight.

I upped mine to 40psi today and I was running 22.8mpg, managed 24.0mpg today and didn't exactly make the best at the lights. I'll keep running it at 40....update in a few days