Reduced MPG after service.

[backtothe80s]

I bit the bullet and paid my local indy to do a service on the modern...

Asked for 0w20 as per toyota spec but they advised 5w30 is fine and used it. Wasn't sure but went with it.. Spent ages researching whether it'll be OK.

My MPG has literally dropped 10mpg since the service.

Any advice? Could it be the change in grade?

[vitesseefi]

What vehicle? Petrol or diesel?

Seriously doubt change in oil grade would make a measurable difference let alone 10 mpg.

I’d be looking at air filter, vacuum pipe work and that kind of area, though I’d have thought anything significant enough to give around 25% change to mpg would put a check engine light on.

Also low tyre pressures and dragging brakes can have effects of that kind of order.

Nick

[ferny]

Also, when was the last time you checked the MPG?

Cold starts and short journeys with lights and heaters on will cause it to plummet. I can get 16mpg commuting in winter but 30mpg in summer.

[tubthumper]

Have you recently filled up with e10, as I've noticed a drop in mpg when using this over e5?

[gtviva]

I think if the book states 0w20 oil I would want 0w20 oil, sounds like the indy didnt want to buy any in especially which perhaps sums up the job?

[comfortablynumb]

Another reason I never leave my cars with anyone, even if they're being MOT'd I'm still standing about like an expectant father.
Helps that my local MOT guys are quite happy for me to get under the ramp and have a poke about.

[xbl]

The book will have a varying chart of oil viscosity based on minimum and maximum ambient temperatures the vehicle will operate in. So 0w20 may well be replaced with a different grade with no issues.

[kevins]

More important than the grade is that it is the right spec, modern cars have specific addative packs for specific engines.

[swampy76]

The new is e10 is having an effect on mpg abs emissions

[ChasR]

A couple of things will affect it

-E10 fuel : Calorific value of ethanol is lower. Even with E5, the MPG dropped, albeit not notably.
-Colder weather : We've had a cold snap. Colder journeys will affect MPG.

Not that it mattes but what car is it?

[gte86]

Dec 11, 2021 0:49:44 GMT backtothe80s said:

I bit the bullet and paid my local indy to do a service on the modern...

Asked for 0w20 as per toyota spec but they advised 5w30 is fine and used it. Wasn't sure but went with it.. Spent ages researching whether it'll be OK.

My MPG has literally dropped 10mpg since the service.

Any advice? Could it be the change in grade?

Have you reset all counters and done decent mileage since? Cars are left to idle alot when serviced to get up to temperature etc.
This has an effect on mpg displays.

[duggers]

Oil viscocity will not affect MPG to that extent.
More likley they've not reconnected sometghing properly, vacuum pipe or electrical connector to a sensor.